It's more comfortable for a child to be cuddled by a parent than for a teenager

Anxiety

Anxiety is a normal reaction to stressful situations. But in some cases, it becomes excessive and can cause sufferers to dread everyday situations.
This type of steady, all-over anxiety is called Generalized Anxiety Disorder.

Fear

Fear is a vital response to physical and emotional danger—if we didn't feel it, we couldn't protect ourselves from legitimate threats. But often we fear situations that are far from life-or-death, and thus hang back for no good reason.